Pointers, Allocation, and the Garbage Collector

Pointers

This lesson explains the main concept clearly with beginner-friendly examples and background so you can learn why the code works.

Go exposes pointers (*T) but does not allow pointer arithmetic.

var x int = 10
p := &x        // p points to x
fmt.Println(*p) // 10
*p = 20        // changes x to 20

new vs. make

• new(T) returns a pointer to a zero‑valued T.
• make allocates and initializes slices, maps, and channels.

p := new(int)    // *int, value 0
s := make([]int, 0, 10) // slice with capacity 10

Garbage Collection (GC)

Go’s GC is concurrent, non‑generational and tuned for low‑latency. You generally do not need to free memory manually; just let references go out of scope.

When to be GC‑friendly

• Reuse large buffers (bytes.Buffer) instead of allocating per request.
• Avoid retaining references to huge objects longer than needed.